There is a 'school of thought' that dielectric properties have a
profound effect on the signal passing through a wire. Thus (to pick an
example) we find interconnect, AC power, and loudspeaker cables hand
wrapped in multiple layers of natural fibre, resulting in very thick
and very expensive end products. These wrappings are, presumably,
intended to minimize distortion of the electromagnetic field
propagating along the wire. Indeed, one manufacturer (who shall
remain nameless) cautions not to allow their cables near any plastic
material or synthetic carpets: "The proximity of bad-sounding
dielectric will seriously degrade the sound of even the best cables."
Take note: "seriously degrade." Not "potentially." Not
"theoretically." But "seriously." I will give this source credit for
one thing, though: they make no attempt to explain this phenomenon
using pseudo-scientific jargon. They simply state it as fact. I am
curious to hear your comments. I must disqualify myself from
commenting being one of the benighted souls who never has heard a
difference in cables...